Complex
Primitive
ActivityDefinition
CapabilityStatement
CodeSystem
Composition
ConceptMap
Encounter
Library
List
Measure
MessageHeader
Observation
Patient
PlanDefinition
Questionnaire
Resource
ServiceDefinition
StructureDefinition
StructureMap
ValueSet
default
Base StructureDefinition for StructureDefinition Resource
StructureDefinition
Path
StructureDefinition
Id
StructureDefinition
Cardinality
0 - *
Definition
A definition of a FHIR structure. This resource is used to describe the underlying resources, data types defined in FHIR, and also for describing extensions and constraints on resources and data types.
Comment
Constraint
dom-2 [error]
If the resource is contained in another resource, it SHALL NOT contain nested Resources
dom-1 [error]
If the resource is contained in another resource, it SHALL NOT contain any narrative
dom-4 [error]
If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated
dom-3 [error]
If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource
sdf-9 [error]
In any snapshot or differential, no label, code or requirements on the an element without a "." in the path (e.g. the first element)
sdf-19 [error]
Custom types can only be used in logical models
sdf-16 [error]
All element definitions must have unique ids (snapshot)
sdf-18 [error]
Context Invariants can only be used for extensions
sdf-17 [error]
All element definitions must have unique ids (diff)
sdf-11 [error]
If there's a type, its content must match the path name in the first element of a snapshot
sdf-14 [error]
All element definitions must have an id
sdf-1 [error]
Element paths must be unique unless the structure is a constraint
sdf-7 [error]
If the structure describes a base Resource or Type, the URL has to start with "http://hl7.org/fhir/StructureDefinition/" and the tail must match the id
sdf-6 [error]
A structure must have either a differential, or a snapshot (or both)
sdf-5 [error]
If the structure defines an extension then the structure must have context information
sdf-4 [error]
If the structure is not abstract, then there SHALL be a baseDefinition
Path
StructureDefinition.url
Id
StructureDefinition.url
Type
Cardinality
1 - 1
Definition
An absolute URI that is used to identify this structure definition when it is referenced in a specification, model, design or an instance. This SHALL be a URL, SHOULD be globally unique, and SHOULD be an address at which this structure definition is (or will be) published. The URL SHOULD include the major version of the structure definition. For more information see [Technical and Business Versions](resource.html#versions).
Comment
Can be a urn:uuid: or a urn:oid:, but real http: addresses are preferred. Multiple instances may share the same url if they have a distinct version.
Requirements
Allows the structure definition to be referenced by a single globally unique identifier.
Path
StructureDefinition.identifier
Id
StructureDefinition.identifier
Type
Cardinality
0 - *
Definition
A formal identifier that is used to identify this structure definition when it is represented in other formats, or referenced in a specification, model, design or an instance.
Comment
Typically, this is used for identifiers that can go in an HL7 V3 II (instance identifier) data type, e.g., to identify this structure definition outside of FHIR, where it is not possible to use the logical URI.
Requirements
Allows externally provided and/or usable business identifiers to be easily associated with the module.
Path
StructureDefinition.identifier.Identifier.use
Id
Identifier.use
Type
Cardinality
0 - 1
Definition
The purpose of this identifier.
Comment
This is labeled as "Is Modifier" because applications should not mistake a temporary id for a permanent one. Applications can assume that an identifier is permanent unless it explicitly says that it is temporary.
Requirements
Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers.
Path
StructureDefinition.identifier.Identifier.type
Id
Identifier.type
Type
Cardinality
0 - 1
Definition
A coded type for the identifier that can be used to determine which identifier to use for a specific purpose.
Comment
This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage.
Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type.
Requirements
Allows users to make use of identifiers when the identifier system is not known.
Path
StructureDefinition.identifier.Identifier.type.CodeableConcept.coding
Id
CodeableConcept.coding
Type
Cardinality
0 - *
Definition
A reference to a code defined by a terminology system.
Comment
Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.
Requirements
Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.
Path
StructureDefinition.identifier.Identifier.type.CodeableConcept.coding.Coding.system
Id
Coding.system
Type
Cardinality
0 - 1
Definition
The identification of the code system that defines the meaning of the symbol in the code.
Comment
The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.
Requirements
Need to be unambiguous about the source of the definition of the symbol.
Path
StructureDefinition.identifier.Identifier.type.CodeableConcept.coding.Coding.version
Id
Coding.version
Type
Cardinality
0 - 1
Definition
The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured. and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.
Comment
Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.
Path
StructureDefinition.identifier.Identifier.type.CodeableConcept.coding.Coding.code
Id
Coding.code
Type
Cardinality
0 - 1
Definition
A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).
Comment
Requirements
Need to refer to a particular code in the system.
Path
StructureDefinition.identifier.Identifier.type.CodeableConcept.coding.Coding.display
Id
Coding.display
Type
Cardinality
0 - 1
Definition
A representation of the meaning of the code in the system, following the rules of the system.
Comment
Requirements
Need to be able to carry a human-readable meaning of the code for readers that do not know the system.
Path
StructureDefinition.identifier.Identifier.type.CodeableConcept.coding.Coding.userSelected
Id
Coding.userSelected
Type
Cardinality
0 - 1
Definition
Indicates that this coding was chosen by a user directly - i.e. off a pick list of available items (codes or displays).
Comment
Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely.
Requirements
This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing.
Path
StructureDefinition.identifier.Identifier.system
Id
Identifier.system
Type
Cardinality
0 - 1
Definition
Establishes the namespace for the value - that is, a URL that describes a set values that are unique.
Comment
Requirements
There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers.
Path
StructureDefinition.identifier.Identifier.value
Id
Identifier.value
Type
Cardinality
0 - 1
Definition
The portion of the identifier typically relevant to the user and which is unique within the context of the system.
Comment
If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the [Rendered Value extension](extension-rendered-value.html).
Path
StructureDefinition.identifier.Identifier.period
Id
Identifier.period
Type
Cardinality
0 - 1
Definition
Time period during which identifier is/was valid for use.
Comment
Path
StructureDefinition.identifier.Identifier.period.Period.start
Id
Period.start
Type
Cardinality
0 - 1
Definition
The start of the period. The boundary is inclusive.
Comment
If the low element is missing, the meaning is that the low boundary is not known.
Condition
per-1
Path
StructureDefinition.identifier.Identifier.period.Period.end
Id
Period.end
Type
Cardinality
0 - 1
Definition
The end of the period. If the end of the period is missing, it means that the period is ongoing. The start may be in the past, and the end date in the future, which means that period is expected/planned to end at that time.
Comment
The high value includes any matching date/time. i.e. 2012-02-03T10:00:00 is in a period that has a end value of 2012-02-03.
Condition
per-1
Path
StructureDefinition.identifier.Identifier.assigner
Id
Identifier.assigner
Type
Cardinality
0 - 1
Definition
Organization that issued/manages the identifier.
Comment
The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization.
Path
StructureDefinition.identifier.Identifier.assigner.Reference.reference
Id
Reference.reference
Type
Cardinality
0 - 1
Definition
A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources.
Comment
Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server.
Condition
ref-1
Path
StructureDefinition.identifier.Identifier.assigner.Reference.identifier
Id
Reference.identifier
Type
Cardinality
0 - 1
Definition
An identifier for the other resource. This is used when there is no way to reference the other resource directly, either because the entity is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference.
Comment
When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy.
When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference
Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it.
Path
StructureDefinition.identifier.Identifier.assigner.Reference.identifier.Identifier.use
Id
Identifier.use
Type
Cardinality
0 - 1
Definition
The purpose of this identifier.
Comment
This is labeled as "Is Modifier" because applications should not mistake a temporary id for a permanent one. Applications can assume that an identifier is permanent unless it explicitly says that it is temporary.
Requirements
Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers.
Path
StructureDefinition.identifier.Identifier.assigner.Reference.identifier.Identifier.type
Id
Identifier.type
Type
Cardinality
0 - 1
Definition
A coded type for the identifier that can be used to determine which identifier to use for a specific purpose.
Comment
This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage.
Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type.
Requirements
Allows users to make use of identifiers when the identifier system is not known.
Path
StructureDefinition.identifier.Identifier.assigner.Reference.identifier.Identifier.system
Id
Identifier.system
Type
Cardinality
0 - 1
Definition
Establishes the namespace for the value - that is, a URL that describes a set values that are unique.
Comment
Requirements
There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers.
Path
StructureDefinition.identifier.Identifier.assigner.Reference.identifier.Identifier.value
Id
Identifier.value
Type
Cardinality
0 - 1
Definition
The portion of the identifier typically relevant to the user and which is unique within the context of the system.
Comment
If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the [Rendered Value extension](extension-rendered-value.html).
Path
StructureDefinition.identifier.Identifier.assigner.Reference.identifier.Identifier.period
Id
Identifier.period
Type
Cardinality
0 - 1
Definition
Time period during which identifier is/was valid for use.
Comment
Path
StructureDefinition.identifier.Identifier.assigner.Reference.identifier.Identifier.assigner
Id
Identifier.assigner
Type
Cardinality
0 - 1
Definition
Organization that issued/manages the identifier.
Comment
The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization.
Path
StructureDefinition.identifier.Identifier.assigner.Reference.display
Id
Reference.display
Type
Cardinality
0 - 1
Definition
Plain text narrative that identifies the resource in addition to the resource reference.
Comment
This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it.
Path
StructureDefinition.version
Id
StructureDefinition.version
Type
Cardinality
0 - 1
Definition
The identifier that is used to identify this version of the structure definition when it is referenced in a specification, model, design or instance. This is an arbitrary value managed by the structure definition author and is not expected to be globally unique. For example, it might be a timestamp (e.g. yyyymmdd) if a managed version is not available. There is also no expectation that versions can be placed in a lexicographical sequence.
Comment
There may be different structure definition instances that have the same identifier but different versions. The version can be appended to the url in a reference to allow a refrence to a particular business version of the structure definition with the format [url]|[version].
Path
StructureDefinition.name
Id
StructureDefinition.name
Type
Cardinality
1 - 1
Definition
A natural language name identifying the structure definition. This name should be usable as an identifier for the module by machine processing applications such as code generation.
Comment
The name is not expected to be globally unique. The name should be a simple alpha-numeric type name to ensure that it is computable friendly.
Requirements
Support human navigation and code generation.
Path
StructureDefinition.title
Id
StructureDefinition.title
Type
Cardinality
0 - 1
Definition
A short, descriptive, user-friendly title for the structure definition.
Comment
This name does not need to be machine-processing friendly and may contain punctuation, white-space, etc. Applications don't have to use this name, but can always fall back to it. The title also corresponds to the label for the root element.
Path
StructureDefinition.status
Id
StructureDefinition.status
Type
Cardinality
1 - 1
Definition
The status of this structure definition. Enables tracking the life-cycle of the content.
Comment
Allows filtering of structure definitions that are appropriate for use vs. not.
This is labeled as "Is Modifier" because applications should not use a retired structure definition without due consideration.
Path
StructureDefinition.experimental
Id
StructureDefinition.experimental
Type
Cardinality
0 - 1
Definition
A boolean value to indicate that this structure definition is authored for testing purposes (or education/evaluation/marketing), and is not intended to be used for genuine usage.
Comment
Allows filtering of structure definition that are appropriate for use vs. not. This is labeled as "Is Modifier" because applications should not use an experimental structure definition in production.
Requirements
Enables experimental content to be developed following the same lifecycle that would be used for a production-level structure definition.
Path
StructureDefinition.date
Id
StructureDefinition.date
Type
Cardinality
0 - 1
Definition
The date (and optionally time) when the structure definition was published. The date must change if and when the business version changes and it must change if the status code changes. In addition, it should change when the substantive content of the structure definition changes.
Comment
Note that this is not the same as the resource last-modified-date, since the resource may be a secondary representation of the structure definition. Additional specific dates may be added as extensions or be found by consulting Provenances associated with past versions of the resource.
Path
StructureDefinition.publisher
Id
StructureDefinition.publisher
Type
Cardinality
0 - 1
Definition
The name of the individual or organization that published the structure definition.
Comment
Usually an organization, but may be an individual. The publisher (or steward) of the structure definition is the organization or individual primarily responsible for the maintenance and upkeep of the structure definition. This is not necessarily the same individual or organization that developed and initially authored the content. The publisher is the primary point of contact for questions or issues with the structure definition. This item SHOULD be populated unless the information is available from context.
Requirements
Helps establish the "authority/credibility" of the structure definition. May also allow for contact.
Path
StructureDefinition.contact
Id
StructureDefinition.contact
Type
Cardinality
0 - *
Definition
Contact details to assist a user in finding and communicating with the publisher.
Comment
May be a web site, an email address, a telephone number, etc.
Path
StructureDefinition.contact.ContactDetail.name
Id
ContactDetail.name
Type
Cardinality
0 - 1
Definition
The name of an individual to contact.
Comment
If there is no named individual, the telecom information is for the organization as a whole.
Path
StructureDefinition.contact.ContactDetail.telecom
Id
ContactDetail.telecom
Type
Cardinality
0 - *
Definition
The contact details for the individual (if a name was provided) or the organization.
Comment
Path
StructureDefinition.contact.ContactDetail.telecom.ContactPoint.system
Id
ContactPoint.system
Type
Cardinality
0 - 1
Definition
Telecommunications form for contact point - what communications system is required to make use of the contact.
Comment
Condition
cpt-2
Path
StructureDefinition.contact.ContactDetail.telecom.ContactPoint.value
Id
ContactPoint.value
Type
Cardinality
0 - 1
Definition
The actual contact point details, in a form that is meaningful to the designated communication system (i.e. phone number or email address).
Comment
Additional text data such as phone extension numbers, or notes about use of the contact are sometimes included in the value.
Requirements
Need to support legacy numbers that are not in a tightly controlled format.
Path
StructureDefinition.contact.ContactDetail.telecom.ContactPoint.use
Id
ContactPoint.use
Type
Cardinality
0 - 1
Definition
Identifies the purpose for the contact point.
Comment
This is labeled as "Is Modifier" because applications should not mistake a temporary or old contact etc.for a current/permanent one. Applications can assume that a contact is current unless it explicitly says that it is temporary or old.
Requirements
Need to track the way a person uses this contact, so a user can choose which is appropriate for their purpose.
Path
StructureDefinition.contact.ContactDetail.telecom.ContactPoint.rank
Id
ContactPoint.rank
Type
Cardinality
0 - 1
Definition
Specifies a preferred order in which to use a set of contacts. Contacts are ranked with lower values coming before higher values.
Comment
Note that rank does not necessarily follow the order in which the contacts are represented in the instance.
Path
StructureDefinition.contact.ContactDetail.telecom.ContactPoint.period
Id
ContactPoint.period
Type
Cardinality
0 - 1
Definition
Time period when the contact point was/is in use.
Comment
Path
StructureDefinition.contact.ContactDetail.telecom.ContactPoint.period.Period.start
Id
Period.start
Type
Cardinality
0 - 1
Definition
The start of the period. The boundary is inclusive.
Comment
If the low element is missing, the meaning is that the low boundary is not known.
Condition
per-1
Path
StructureDefinition.contact.ContactDetail.telecom.ContactPoint.period.Period.end
Id
Period.end
Type
Cardinality
0 - 1
Definition
The end of the period. If the end of the period is missing, it means that the period is ongoing. The start may be in the past, and the end date in the future, which means that period is expected/planned to end at that time.
Comment
The high value includes any matching date/time. i.e. 2012-02-03T10:00:00 is in a period that has a end value of 2012-02-03.
Condition
per-1
Path
StructureDefinition.description
Id
StructureDefinition.description
Type
Cardinality
0 - 1
Definition
A free text natural language description of the structure definition from a consumer's perspective.
Comment
This description can be used to capture details such as why the structure definition was built, comments about misuse, instructions for clinical use and interpretation, literature references, examples from the paper world, etc. It is not a rendering of the structure definition as conveyed in the 'text' field of the resource itself. This item SHOULD be populated unless the information is available from context (e.g. the language of the profile is presumed to be the predominant language in the place the profile was created).
Path
StructureDefinition.useContext
Id
StructureDefinition.useContext
Type
Cardinality
0 - *
Definition
The content was developed with a focus and intent of supporting the contexts that are listed. These terms may be used to assist with indexing and searching for appropriate structure definition instances.
Comment
When multiple useContexts are specified, there is no expectation whether all or any of the contexts apply.
Requirements
Assist in searching for appropriate content.
Path
StructureDefinition.useContext.UsageContext.code
Id
UsageContext.code
Type
Cardinality
1 - 1
Definition
A code that identifies the type of context being specified by this usage context.
Comment
Path
StructureDefinition.useContext.UsageContext.code.Coding.system
Id
Coding.system
Type
Cardinality
0 - 1
Definition
The identification of the code system that defines the meaning of the symbol in the code.
Comment
The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.
Requirements
Need to be unambiguous about the source of the definition of the symbol.
Path
StructureDefinition.useContext.UsageContext.code.Coding.version
Id
Coding.version
Type
Cardinality
0 - 1
Definition
The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured. and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.
Comment
Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.
Path
StructureDefinition.useContext.UsageContext.code.Coding.code
Id
Coding.code
Type
Cardinality
0 - 1
Definition
A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).
Comment
Requirements
Need to refer to a particular code in the system.
Path
StructureDefinition.useContext.UsageContext.code.Coding.display
Id
Coding.display
Type
Cardinality
0 - 1
Definition
A representation of the meaning of the code in the system, following the rules of the system.
Comment
Requirements
Need to be able to carry a human-readable meaning of the code for readers that do not know the system.
Path
StructureDefinition.useContext.UsageContext.code.Coding.userSelected
Id
Coding.userSelected
Type
Cardinality
0 - 1
Definition
Indicates that this coding was chosen by a user directly - i.e. off a pick list of available items (codes or displays).
Comment
Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely.
Requirements
This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing.
Path
StructureDefinition.useContext.UsageContext.value[x]
Id
UsageContext.value[x]
Type
Cardinality
1 - 1
Definition
A value that defines the context specified in this context of use. The interpretation of the value is defined by the code.
Comment
Path
StructureDefinition.useContext.UsageContext.value[x].CodeableConcept.coding
Id
CodeableConcept.coding
Type
Cardinality
0 - *
Definition
A reference to a code defined by a terminology system.
Comment
Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.
Requirements
Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.
Path
StructureDefinition.useContext.UsageContext.value[x].CodeableConcept.coding.Coding.system
Id
Coding.system
Type
Cardinality
0 - 1
Definition
The identification of the code system that defines the meaning of the symbol in the code.
Comment
The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.
Requirements
Need to be unambiguous about the source of the definition of the symbol.
Path
StructureDefinition.useContext.UsageContext.value[x].CodeableConcept.coding.Coding.version
Id
Coding.version
Type
Cardinality
0 - 1
Definition
The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured. and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.
Comment
Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.
Path
StructureDefinition.useContext.UsageContext.value[x].CodeableConcept.coding.Coding.code
Id
Coding.code
Type
Cardinality
0 - 1
Definition
A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).
Comment
Requirements
Need to refer to a particular code in the system.
Path
StructureDefinition.useContext.UsageContext.value[x].CodeableConcept.coding.Coding.display
Id
Coding.display
Type
Cardinality
0 - 1
Definition
A representation of the meaning of the code in the system, following the rules of the system.
Comment
Requirements
Need to be able to carry a human-readable meaning of the code for readers that do not know the system.
Path
StructureDefinition.useContext.UsageContext.value[x].CodeableConcept.coding.Coding.userSelected
Id
Coding.userSelected
Type
Cardinality
0 - 1
Definition
Indicates that this coding was chosen by a user directly - i.e. off a pick list of available items (codes or displays).
Comment
Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely.
Requirements
This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing.
Path
StructureDefinition.jurisdiction
Id
StructureDefinition.jurisdiction
Type
Cardinality
0 - *
Definition
A legal or geographic region in which the structure definition is intended to be used.
Comment
It may be possible for the structure definition to be used in jurisdictions other than those for which it was originally designed or intended.
Path
StructureDefinition.jurisdiction.CodeableConcept.coding
Id
CodeableConcept.coding
Type
Cardinality
0 - *
Definition
A reference to a code defined by a terminology system.
Comment
Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.
Requirements
Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.
Path
StructureDefinition.jurisdiction.CodeableConcept.coding.Coding.system
Id
Coding.system
Type
Cardinality
0 - 1
Definition
The identification of the code system that defines the meaning of the symbol in the code.
Comment
The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.
Requirements
Need to be unambiguous about the source of the definition of the symbol.
Path
StructureDefinition.jurisdiction.CodeableConcept.coding.Coding.version
Id
Coding.version
Type
Cardinality
0 - 1
Definition
The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured. and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.
Comment
Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.
Path
StructureDefinition.jurisdiction.CodeableConcept.coding.Coding.code
Id
Coding.code
Type
Cardinality
0 - 1
Definition
A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).
Comment
Requirements
Need to refer to a particular code in the system.
Path
StructureDefinition.jurisdiction.CodeableConcept.coding.Coding.display
Id
Coding.display
Type
Cardinality
0 - 1
Definition
A representation of the meaning of the code in the system, following the rules of the system.
Comment
Requirements
Need to be able to carry a human-readable meaning of the code for readers that do not know the system.
Path
StructureDefinition.jurisdiction.CodeableConcept.coding.Coding.userSelected
Id
Coding.userSelected
Type
Cardinality
0 - 1
Definition
Indicates that this coding was chosen by a user directly - i.e. off a pick list of available items (codes or displays).
Comment
Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely.
Requirements
This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing.
Path
StructureDefinition.purpose
Id
StructureDefinition.purpose
Type
Cardinality
0 - 1
Definition
Explaination of why this structure definition is needed and why it has been designed as it has.
Comment
This element does not describe the usage of the structure definition Instead it provides traceability of ''why'' the resource is either needed or ''why'' it is defined as it is. This may be used to point to source materials or specifications that drove the structure of this structure definition.
Path
StructureDefinition.copyright
Id
StructureDefinition.copyright
Type
Cardinality
0 - 1
Definition
A copyright statement relating to the structure definition and/or its contents. Copyright statements are generally legal restrictions on the use and publishing of the structure definition.
Comment
Requirements
Consumers must be able to determine any legal restrictions on the use of the structure definition and/or its content.
Path
StructureDefinition.keyword
Id
StructureDefinition.keyword
Type
Cardinality
0 - *
Definition
A set of key words or terms from external terminologies that may be used to assist with indexing and searching of templates.
Comment
Requirements
Assist in searching for appropriate StructureDefinitions.
Path
StructureDefinition.keyword.Coding.system
Id
Coding.system
Type
Cardinality
0 - 1
Definition
The identification of the code system that defines the meaning of the symbol in the code.
Comment
The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.
Requirements
Need to be unambiguous about the source of the definition of the symbol.
Path
StructureDefinition.keyword.Coding.version
Id
Coding.version
Type
Cardinality
0 - 1
Definition
The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured. and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.
Comment
Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.
Path
StructureDefinition.keyword.Coding.code
Id
Coding.code
Type
Cardinality
0 - 1
Definition
A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).
Comment
Requirements
Need to refer to a particular code in the system.
Path
StructureDefinition.keyword.Coding.display
Id
Coding.display
Type
Cardinality
0 - 1
Definition
A representation of the meaning of the code in the system, following the rules of the system.
Comment
Requirements
Need to be able to carry a human-readable meaning of the code for readers that do not know the system.
Path
StructureDefinition.keyword.Coding.userSelected
Id
Coding.userSelected
Type
Cardinality
0 - 1
Definition
Indicates that this coding was chosen by a user directly - i.e. off a pick list of available items (codes or displays).
Comment
Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely.
Requirements
This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing.
Path
StructureDefinition.fhirVersion
Id
StructureDefinition.fhirVersion
Type
Cardinality
0 - 1
Definition
The version of the FHIR specification on which this StructureDefinition is based - this is the formal version of the specification, without the revision number, e.g. [publication].[major].[minor], which is 3.0.2 for this version.
Comment
A StructureDefinition does not need to specify the target it applies to,as StructureDefinitions will often be valid across multiple versions of FHIR. FHIR tooling can determine whether a StructureDefinition is consistent with a particular StructureDefinition if desired.
Path
StructureDefinition.mapping
Id
StructureDefinition.mapping
Type
Cardinality
0 - *
Definition
An external specification that the content is mapped to.
Comment
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
sdf-2 [error]
Must have at least a name or a uri (or both)
Path
StructureDefinition.mapping.identity
Id
StructureDefinition.mapping.identity
Type
Cardinality
1 - 1
Definition
An Internal id that is used to identify this mapping set when specific mappings are made.
Comment
The specification is described once, with general comments, and then specific mappings are made that reference this declaration.
Path
StructureDefinition.mapping.uri
Id
StructureDefinition.mapping.uri
Type
Cardinality
0 - 1
Definition
An absolute URI that identifies the specification that this mapping is expressed to.
Comment
A formal identity for the specification being mapped to helps with identifying maps consistently.
Condition
sdf-2
Path
StructureDefinition.mapping.name
Id
StructureDefinition.mapping.name
Type
Cardinality
0 - 1
Definition
A name for the specification that is being mapped to.
Comment
Condition
sdf-2
Path
StructureDefinition.mapping.comment
Id
StructureDefinition.mapping.comment
Type
Cardinality
0 - 1
Definition
Comments about this mapping, including version notes, issues, scope limitations, and other important notes for usage.
Comment
Path
StructureDefinition.kind
Id
StructureDefinition.kind
Type
Cardinality
1 - 1
Definition
Defines the kind of structure that this definition is describing.
Comment
Path
StructureDefinition.abstract
Id
StructureDefinition.abstract
Type
Cardinality
1 - 1
Definition
Whether structure this definition describes is abstract or not - that is, whether the structure is not intended to be instantiated. For Resources and Data types, abstract types will never be exchanged between systems.
Comment
Abstract Resources cannot be instantiated - a concrete sub-type must be used. Abstract datatypes and extensions cannot be used in an instance. For logical models, the exact implication of "abstract" will rest with the author, depending how the logical model is used. Flagging a constraint structure as abstract conveys design intent but makes no difference to how the structure definition is handled. Note that inline declared elements that are given the type "Element" in the profile, but have children described, are anonymous concrete types that specialise Element.
Path
StructureDefinition.contextType
Id
StructureDefinition.contextType
Type
Cardinality
0 - 1
Definition
If this is an extension, Identifies the context within FHIR resources where the extension can be used.
Comment
Condition
sdf-5
Path
StructureDefinition.context
Id
StructureDefinition.context
Type
Cardinality
0 - *
Definition
Identifies the types of resource or data type elements to which the extension can be applied.
Comment
If the context is an element that can have multiple types, then use (e.g.) value[x] if the extension works on all choice types, or otherwise an enumeration of explicitly named elements if not. Note that a context of "string" doesn't mean that the extension can be used with one of the string patterns such as "id" etc.
Condition
sdf-5
Path
StructureDefinition.contextInvariant
Id
StructureDefinition.contextInvariant
Type
Cardinality
0 - *
Definition
A set of rules as Fluent Invariants about when the extension can be used (e.g. co-occurrence variants for the extension).
Comment
All the rules must be true. When evaluating the invariant, the fluentpath focus is the element that holds the extension, and %extension refers to the extension itself.
Condition
sdf-18
Path
StructureDefinition.type
Id
StructureDefinition.type
Type
Cardinality
1 - 1
Definition
The type this structure describes. If the derivation kind is 'specialization' then this is the master definition for a type, and there is always one of these (a data type, an extension, a resource, including abstract ones). Otherwise the structure definition is a constraint on the stated type (and in this case, the type cannot be an abstract type).
Comment
Note that in the case of constraints, the type could be determined by chasing through the baseDefinition references until a concrete structure (derivation = specialization) is reached, or by looking at the path of the first element in the snapshot - if present - but providing the type directly makes for simpler tooling and indexing.
Binding
Strength
extensible
Description
Either a resource or a data type, including logical model types
ValueSet
Condition
sdf-4
sdf-11
Path
StructureDefinition.baseDefinition
Id
StructureDefinition.baseDefinition
Type
Cardinality
0 - 1
Definition
An absolute URI that is the base structure from which this type is derived, either by specialization or constraint.
Comment
If differential constraints are specified in this structure, they are applied to the base in a "differential" fashion. If there is no base, then the differential constraints cannot be provided (snapshot only). Differential structures are useful for the editing perspective, and snapshot structures are suitable for operational use. The FHIR Project provides a number of tools/services to populate snapshots from differential constraints. Logical Models have a base of "Element" or another logical model.
Condition
sdf-4
Path
StructureDefinition.derivation
Id
StructureDefinition.derivation
Type
Cardinality
0 - 1
Definition
How the type relates to the baseDefinition.
Comment
If the definition is a specialization, then it adds new elements in the differential, and the snapshot includes the inherited elements.
If the definition is a constraint, then it can not define new elements, it can only make new rules about existing content (see [Profiling Resources](profiling.html#resources)).
Path
StructureDefinition.snapshot
Id
StructureDefinition.snapshot
Type
Cardinality
0 - 1
Definition
A snapshot view is expressed in a stand alone form that can be used and interpreted without considering the base StructureDefinition.
Comment
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
sdf-15 [error]
The first element in a snapshot has no type
sdf-8 [error]
In any snapshot, all the elements must be in the specified type
sdf-3 [error]
Each element definition in a snapshot must have a formal definition and cardinalities
Condition
sdf-6
Path
StructureDefinition.snapshot.element
Id
StructureDefinition.snapshot.element
Type
Cardinality
1 - *
Definition
Captures constraints on each element within the resource.
Comment
Condition
sdf-3
Path
StructureDefinition.snapshot.element.ElementDefinition.path
Id
ElementDefinition.path
Type
Cardinality
1 - 1
Definition
The path identifies the element and is expressed as a "."-separated list of ancestor elements, beginning with the name of the resource or extension.
Comment
Path
StructureDefinition.snapshot.element.ElementDefinition.representation
Id
ElementDefinition.representation
Type
Cardinality
0 - *
Definition
Codes that define how this element is represented in instances, when the deviation varies from the normal case.
Comment
In resources, this is rarely used except for special cases where the representation deviates from the normal, and can only be done in the base standard (and profiles must reproduce what the base standard does). This element is used quite commonly in Logical models when the logical models represent a specific serialization format (e.g. CDA, v2 etc).
Path
StructureDefinition.snapshot.element.ElementDefinition.sliceName
Id
ElementDefinition.sliceName
Type
Cardinality
0 - 1
Definition
The name of this element definition slice, when slicing is working. The name must be a token with no dots or spaces. This is a unique name referring to a specific set of constraints applied to this element, used to provide a name to different slices of the same element.
Comment
The name SHALL be unique within the structure within the context of the constrained resource element. (Though to avoid confusion, uniqueness across all elements is recommended.).
Requirements
May also be used for code generation purposes.
Path
StructureDefinition.snapshot.element.ElementDefinition.label
Id
ElementDefinition.label
Type
Cardinality
0 - 1
Definition
A single preferred label which is the text to display beside the element indicating its meaning or to use to prompt for the element in a user display or form.
Comment
See also the extension (http://hl7.org/fhir/StructureDefinition/elementdefinition-question)[extension-elementdefinition-question.html].
Path
StructureDefinition.snapshot.element.ElementDefinition.code
Id
ElementDefinition.code
Type
Cardinality
0 - *
Definition
A code that has the same meaning as the element in a particular terminology.
Comment
The concept SHALL be properly aligned with the data element definition and other constraints, as defined in the code system, including relationships, of any code listed here. Where multiple codes exist in a terminology that could correspond to the data element, the most granular code(s) should be selected, so long as they are not more restrictive than the data element itself. The mappings may be used to provide more or less granular or structured equivalences in the code system.
Requirements
Links the meaning of an element to an external terminology, and is very useful for searching and indexing.
Path
StructureDefinition.snapshot.element.ElementDefinition.code.Coding.system
Id
Coding.system
Type
Cardinality
0 - 1
Definition
The identification of the code system that defines the meaning of the symbol in the code.
Comment
The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.
Requirements
Need to be unambiguous about the source of the definition of the symbol.
Path
StructureDefinition.snapshot.element.ElementDefinition.code.Coding.version
Id
Coding.version
Type
Cardinality
0 - 1
Definition
The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured. and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.
Comment
Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.
Path
StructureDefinition.snapshot.element.ElementDefinition.code.Coding.code
Id
Coding.code
Type
Cardinality
0 - 1
Definition
A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).
Comment
Requirements
Need to refer to a particular code in the system.
Path
StructureDefinition.snapshot.element.ElementDefinition.code.Coding.display
Id
Coding.display
Type
Cardinality
0 - 1
Definition
A representation of the meaning of the code in the system, following the rules of the system.
Comment
Requirements
Need to be able to carry a human-readable meaning of the code for readers that do not know the system.
Path
StructureDefinition.snapshot.element.ElementDefinition.code.Coding.userSelected
Id
Coding.userSelected
Type
Cardinality
0 - 1
Definition
Indicates that this coding was chosen by a user directly - i.e. off a pick list of available items (codes or displays).
Comment
Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely.
Requirements
This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing.
Path
StructureDefinition.snapshot.element.ElementDefinition.slicing
Id
ElementDefinition.slicing
Type
Cardinality
0 - 1
Definition
Indicates that the element is sliced into a set of alternative definitions (i.e. in a structure definition, there are multiple different constraints on a single element in the base resource). Slicing can be used in any resource that has cardinality ..* on the base resource, or any resource with a choice of types. The set of slices is any elements that come after this in the element sequence that have the same path, until a shorter path occurs (the shorter path terminates the set).
Comment
The first element in the sequence, the one that carries the slicing, is the definition that applies to all the slices. This is based on the unconstrained element, but can apply any constraints as appropriate. This may include the common constraints on the children of the element.
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
eld-1 [error]
If there are no discriminators, there must be a definition
Path
StructureDefinition.snapshot.element.ElementDefinition.slicing.discriminator
Id
ElementDefinition.slicing.discriminator
Type
Cardinality
0 - *
Definition
Designates which child elements are used to discriminate between the slices when processing an instance. If one or more discriminators are provided, the value of the child elements in the instance data SHALL completely distinguish which slice the element in the resource matches based on the allowed values for those elements in each of the slices.
Comment
If there is no discriminator, the content is hard to process, so this should be avoided. If the base element has a cardinality of ..1, and there is a choice of types, the discriminator must be "@type".
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
Path
StructureDefinition.snapshot.element.ElementDefinition.slicing.discriminator.type
Id
ElementDefinition.slicing.discriminator.type
Type
Cardinality
1 - 1
Definition
How the element value is interpreted when discrimination is evaluated.
Comment
Path
StructureDefinition.snapshot.element.ElementDefinition.slicing.discriminator.path
Id
ElementDefinition.slicing.discriminator.path
Type
Cardinality
1 - 1
Definition
A FHIRPath expression, using a restricted subset of FHIRPath, that is used to identify the element on which discrimination is based.
Comment
The only FHIRPath functions that are allowed are resolve(), and extension(url).
Path
StructureDefinition.snapshot.element.ElementDefinition.slicing.description
Id
ElementDefinition.slicing.description
Type
Cardinality
0 - 1
Definition
A human-readable text description of how the slicing works. If there is no discriminator, this is required to be present to provide whatever information is possible about how the slices can be differentiated.
Comment
If it's really not possible to differentiate them, the design should be re-evaluated to make the content usable.
Condition
eld-1
Path
StructureDefinition.snapshot.element.ElementDefinition.slicing.ordered
Id
ElementDefinition.slicing.ordered
Type
Cardinality
0 - 1
Definition
If the matching elements have to occur in the same order as defined in the profile.
Comment
Order should only be required when it is a pressing concern for presentation. Profile authors should consider making the order a feature of the rules about the narrative, not the rules about the data - requiring ordered data makes the profile much less re-usable.
Path
StructureDefinition.snapshot.element.ElementDefinition.slicing.rules
Id
ElementDefinition.slicing.rules
Type
Cardinality
1 - 1
Definition
Whether additional slices are allowed or not. When the slices are ordered, profile authors can also say that additional slices are only allowed at the end.
Comment
Allowing additional elements makes for a much for flexible template - it's open for use in wider contexts, but also means that the content of the resource is not closed, and applications have to decide how to handle content not described by the profile.
Path
StructureDefinition.snapshot.element.ElementDefinition.short
Id
ElementDefinition.short
Type
Cardinality
0 - 1
Definition
A concise description of what this element means (e.g. for use in autogenerated summaries).
Comment
May change the term to provide language more appropriate to the context of the profile or to reflect slicing.
Path
StructureDefinition.snapshot.element.ElementDefinition.definition
Id
ElementDefinition.definition
Type
Cardinality
0 - 1
Definition
Provides a complete explanation of the meaning of the data element for human readability. For the case of elements derived from existing elements (e.g. constraints), the definition SHALL be consistent with the base definition, but convey the meaning of the element in the particular context of use of the resource.
Comment
It is easy for a different definition to change the meaning of an element and this can have nasty downstream consequences. Please be careful when providing definitions.
Requirements
To allow a user to state the usage of an element in a particular context.
Path
StructureDefinition.snapshot.element.ElementDefinition.comment
Id
ElementDefinition.comment
Type
Cardinality
0 - 1
Definition
Explanatory notes and implementation guidance about the data element, including notes about how to use the data properly, exceptions to proper use, etc.
Comment
If it is possible to capture usage rules using constraints, that mechanism should be used in preference to this element.
Path
StructureDefinition.snapshot.element.ElementDefinition.requirements
Id
ElementDefinition.requirements
Type
Cardinality
0 - 1
Definition
This element is for traceability of why the element was created and why the constraints exist as they do. This may be used to point to source materials or specifications that drove the structure of this element.
Comment
This element does not describe the usage of the element (that's done in comments), rather it's for traceability of *why* the element is either needed or why the constraints exist as they do. This may be used to point to source materials or specifications that drove the structure of this data element.
Path
StructureDefinition.snapshot.element.ElementDefinition.alias
Id
ElementDefinition.alias
Type
Cardinality
0 - *
Definition
Identifies additional names by which this element might also be known.
Comment
Requirements
Allows for better easier recognition of the element by multiple communities, including international communities.
Path
StructureDefinition.snapshot.element.ElementDefinition.min
Id
ElementDefinition.min
Type
Cardinality
0 - 1
Definition
The minimum number of times this element SHALL appear in the instance.
Comment
Condition
eld-2
Path
StructureDefinition.snapshot.element.ElementDefinition.max
Id
ElementDefinition.max
Type
Cardinality
0 - 1
Definition
The maximum number of times this element is permitted to appear in the instance.
Comment
Constraint
eld-3 [error]
Max SHALL be a number or "*"
Condition
eld-3
eld-2
Path
StructureDefinition.snapshot.element.ElementDefinition.base
Id
ElementDefinition.base
Type
Cardinality
0 - 1
Definition
Information about the base definition of the element, provided to make it unnecessary for tools to trace the deviation of the element through the derived and related profiles. This information is provided when the element definition is not the original definition of an element - i.g. either in a constraint on another type, or for elements from a super type in a snap shot.
Comment
The base information does not carry any information that could not be determined from the path and related profiles, but making this determination requires both that the related profiles are available, and that the algorithm to determine them be available. So they are deformalised into this location for tooling convenience, and to ensure that the base information is available without dependencies.
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
Path
StructureDefinition.snapshot.element.ElementDefinition.base.path
Id
ElementDefinition.base.path
Type
Cardinality
1 - 1
Definition
The Path that identifies the base element - this matches the ElementDefinition.path for that element. Across FHIR, there is only one base definition of any element - that is, an element definition on a [StructureDefinition](structuredefinition.html#) without a StructureDefinition.base.
Comment
Path
StructureDefinition.snapshot.element.ElementDefinition.base.min
Id
ElementDefinition.base.min
Type
Cardinality
1 - 1
Definition
Minimum cardinality of the base element identified by the path.
Comment
This is provided for consistency with max, and may affect code generation of mandatory elements of the base resource are generated differently (some reference implementations have done this).
Path
StructureDefinition.snapshot.element.ElementDefinition.base.max
Id
ElementDefinition.base.max
Type
Cardinality
1 - 1
Definition
Maximum cardinality of the base element identified by the path.
Comment
This is provided to code generation, since the serialization representation in JSON differs depending on whether the base element has max > 1. Also, some forms of code generation may differ.
Path
StructureDefinition.snapshot.element.ElementDefinition.contentReference
Id
ElementDefinition.contentReference
Type
Cardinality
0 - 1
Definition
Identifies the identity of an element defined elsewhere in the profile whose content rules should be applied to the current element.
Comment
Condition
eld-5
Path
StructureDefinition.snapshot.element.ElementDefinition.type
Id
ElementDefinition.type
Type
Cardinality
0 - *
Definition
The data type or resource that the value of this element is permitted to be.
Comment
The Type of the element can be left blank in a differential constraint, in which case the type is inherited from the resource. Abstract types are not permitted to appear as a type when multiple types are listed. (I.e. Abstract types cannot be part of a choice).
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
eld-4 [error]
Aggregation may only be specified if one of the allowed types for the element is a resource
Condition
eld-13
Path
StructureDefinition.snapshot.element.ElementDefinition.type.code
Id
ElementDefinition.type.code
Type
Cardinality
1 - 1
Definition
URL of Data type or Resource that is a(or the) type used for this element. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition e.g. "string" is a reference to http://hl7.org/fhir/StructureDefinition/string. Absolute URLs are only allowed in logical models.
Comment
If the element is a reference to another resource, this element contains "Reference", and the targetProfile element defines what resources can be referenced. The targetProfile may be a reference to the general definition of a resource (e.g. http://hl7.org/fhir/StructureDefinition/Patient). There would be one pair of type/code for each allowed target resource type.
Path
StructureDefinition.snapshot.element.ElementDefinition.type.profile
Id
ElementDefinition.type.profile
Type
Cardinality
0 - 1
Definition
Identifies a profile structure or implementation Guide that SHALL hold for the datatype this element refers to. Can be a local reference - to a contained StructureDefinition, or a reference to another StructureDefinition or Implementation Guide by a canonical URL. When an implementation guide is specified, the resource SHALL conform to at least one profile defined in the implementation guide.
Comment
Path
StructureDefinition.snapshot.element.ElementDefinition.type.targetProfile
Id
ElementDefinition.type.targetProfile
Type
Cardinality
0 - 1
Definition
Identifies a profile structure or implementation Guide that SHALL hold for the target of the reference this element refers to. Can be a local reference - to a contained StructureDefinition, or a reference to another StructureDefinition or Implementation Guide by a canonical URL. When an implementation guide is specified, the resource SHALL conform to at least one profile defined in the implementation guide.
Comment
Path
StructureDefinition.snapshot.element.ElementDefinition.type.aggregation
Id
ElementDefinition.type.aggregation
Type
Cardinality
0 - *
Definition
If the type is a reference to another resource, how the resource is or can be aggregated - is it a contained resource, or a reference, and if the context is a bundle, is it included in the bundle.
Comment
Condition
eld-4
Path
StructureDefinition.snapshot.element.ElementDefinition.type.versioning
Id
ElementDefinition.type.versioning
Type
Cardinality
0 - 1
Definition
Whether this reference needs to be version specific or version independent, or whether either can be used.
Comment
The base specification never makes a rule as to which form is allowed, but implementation guides may do this.
Path
StructureDefinition.snapshot.element.ElementDefinition.defaultValue[x]
Id
ElementDefinition.defaultValue[x]
Type
Cardinality
0 - 1
Definition
The value that should be used if there is no value stated in the instance (e.g. 'if not otherwise specified, the abstract is false').
Comment
Default values can only be specified on a resource, data type, or extension definition, and never in a profile that applies to one of these. Specifying a default value means that the property can never been unknown - it must always have a value. Further, the default value can never be changed. For these reasons, default values are (and should be) used extremely sparingly.
Condition
eld-15
Path
StructureDefinition.snapshot.element.ElementDefinition.meaningWhenMissing
Id
ElementDefinition.meaningWhenMissing
Type
Cardinality
0 - 1
Definition
The Implicit meaning that is to be understood when this element is missing (e.g. 'when this element is missing, the period is ongoing'.
Comment
Implicit meanings for missing values can only be specified on a resource, data type, or extension definition, and never in a profile that applies to one of these. An implicit meaning for a missing value can never be changed, and specifying one has the consequence that constraining its use in profiles eliminates use cases as possibilities, not merely moving them out of scope.
Condition
eld-15
Path
StructureDefinition.snapshot.element.ElementDefinition.orderMeaning
Id
ElementDefinition.orderMeaning
Type
Cardinality
0 - 1
Definition
If present, indicates that the order of the repeating element has meaning and describes what that meaning is. If absent, it means that the order of the element has no meaning.
Comment
This element can only be asserted on repeating elements and can only be introduced when defining resources or data types. It can be further refined profiled elements but if absent in the base type, a profile cannot assert meaning.
Path
StructureDefinition.snapshot.element.ElementDefinition.fixed[x]
Id
ElementDefinition.fixed[x]
Type
Cardinality
0 - 1
Definition
Specifies a value that SHALL be exactly the value for this element in the instance. For purposes of comparison, non-significant whitespace is ignored, and all values must be an exact match (case and accent sensitive). Missing elements/attributes must also be missing.
Comment
This is not recommended for Coding and CodeableConcept since these often have highly contextual properties such as version or display.
Condition
eld-5
eld-6
eld-8
Path
StructureDefinition.snapshot.element.ElementDefinition.pattern[x]
Id
ElementDefinition.pattern[x]
Type
Cardinality
0 - 1
Definition
Specifies a value that the value in the instance SHALL follow - that is, any value in the pattern must be found in the instance. Other additional values may be found too. This is effectively constraint by example. The values of elements present in the pattern must match exactly (case-sensitive, accent-sensitive, etc.).
Comment
Mostly used for fixing values of CodeableConcept. At present, pattern[x] is not recommended as a basis for slicing while issues related to this are investigated during the STU period.
Condition
eld-5
eld-7
eld-8
Path
StructureDefinition.snapshot.element.ElementDefinition.example
Id
ElementDefinition.example
Type
Cardinality
0 - *
Definition
A sample value for this element demonstrating the type of information that would typically be found in the element.
Comment
Examples will most commonly be present for data where it's not implicitly obvious from either the data type or value set what the values might be. (I.e. Example values for dates or quantities would generally be unnecessary.) If the example value is fully populated, the publication tool can generate an instance automatically.
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
Path
StructureDefinition.snapshot.element.ElementDefinition.example.label
Id
ElementDefinition.example.label
Type
Cardinality
1 - 1
Definition
Describes the purpose of this example amoung the set of examples.
Comment
Path
StructureDefinition.snapshot.element.ElementDefinition.example.value[x]
Id
ElementDefinition.example.value[x]
Type
Cardinality
1 - 1
Definition
The actual value for the element, which must be one of the types allowed for this element.
Comment
Path
StructureDefinition.snapshot.element.ElementDefinition.minValue[x]
Id
ElementDefinition.minValue[x]
Type
Cardinality
0 - 1
Definition
The minimum allowed value for the element. The value is inclusive. This is allowed for the types date, dateTime, instant, time, decimal, integer, and Quantity.
Comment
Except for date/date/instant, the type of the minValue[x] SHALL be the same as the specified type of the element. For the date/dateTime/instant values, the type of minValue[x] SHALL be either the same, or a a [Duration](datatypes.html#duration) which specifies a relative time limit to the current time. The duration value is positive, and is subtracted from the current clock to determine the minimum allowable value. A minimum value for a Quantity is interpreted as an canonical minimum - e.g. you cannot provide 100mg if the minimum value is 10g.
Path
StructureDefinition.snapshot.element.ElementDefinition.maxValue[x]
Id
ElementDefinition.maxValue[x]
Type
Cardinality
0 - 1
Definition
The maximum allowed value for the element. The value is inclusive. This is allowed for the types date, dateTime, instant, time, decimal, integer, and Quantity.
Comment
Except for date/date/instant, the type of the maxValue[x] SHALL be the same as the specified type of the element. For the date/dateTime/instant values, the type of maxValue[x] SHALL be either the same, or a a [Duration](datatypes.html#duration) which specifies a relative time limit to the current time. The duration value is positive, and is added to the current clock to determine the maximum allowable value. A maximum value for a Quantity is interpreted as an canonical maximum - e.g. you cannot provide 10g if the maximum value is 50mg.
Path
StructureDefinition.snapshot.element.ElementDefinition.maxLength
Id
ElementDefinition.maxLength
Type
Cardinality
0 - 1
Definition
Indicates the maximum length in characters that is permitted to be present in conformant instances and which is expected to be supported by conformant consumers that support the element.
Comment
Receivers are not required to reject instances that exceed the maximum length. The full length could be stored. In some cases, data might be truncated, though truncation should be undertaken with care and an understanding of the consequences of doing so. If not specified, there is no conformance expectation for length support.
Path
StructureDefinition.snapshot.element.ElementDefinition.condition
Id
ElementDefinition.condition
Type
Cardinality
0 - *
Definition
A reference to an invariant that may make additional statements about the cardinality or value in the instance.
Comment
Path
StructureDefinition.snapshot.element.ElementDefinition.constraint
Id
ElementDefinition.constraint
Type
Cardinality
0 - *
Definition
Formal constraints such as co-occurrence and other constraints that can be computationally evaluated within the context of the instance.
Comment
Constraints should be declared on the "context" element - the lowest element in the hierarchy that is common to all nodes referenced by the constraint.
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
Path
StructureDefinition.snapshot.element.ElementDefinition.constraint.key
Id
ElementDefinition.constraint.key
Type
Cardinality
1 - 1
Definition
Allows identification of which elements have their cardinalities impacted by the constraint. Will not be referenced for constraints that do not affect cardinality.
Comment
Condition
eld-14
Path
StructureDefinition.snapshot.element.ElementDefinition.constraint.requirements
Id
ElementDefinition.constraint.requirements
Type
Cardinality
0 - 1
Definition
Description of why this constraint is necessary or appropriate.
Comment
To be used if the reason for the constraint may not be intuitive to all implementers.
Path
StructureDefinition.snapshot.element.ElementDefinition.constraint.severity
Id
ElementDefinition.constraint.severity
Type
Cardinality
1 - 1
Definition
Identifies the impact constraint violation has on the conformance of the instance.
Comment
This allows constraints to be asserted as "shall" (error) and "should" (warning).
Path
StructureDefinition.snapshot.element.ElementDefinition.constraint.human
Id
ElementDefinition.constraint.human
Type
Cardinality
1 - 1
Definition
Text that can be used to describe the constraint in messages identifying that the constraint has been violated.
Comment
Should be expressed in business terms as much as possible.
Path
StructureDefinition.snapshot.element.ElementDefinition.constraint.expression
Id
ElementDefinition.constraint.expression
Type
Cardinality
1 - 1
Definition
A [FHIRPath](http://hl7.org/fluentpath) expression of constraint that can be executed to see if this constraint is met.
Comment
Requirements
Used by validation tooling tests of the validity of the resource.
Path
StructureDefinition.snapshot.element.ElementDefinition.constraint.xpath
Id
ElementDefinition.constraint.xpath
Type
Cardinality
0 - 1
Definition
An XPath expression of constraint that can be executed to see if this constraint is met.
Comment
Elements SHALL use "f" as the namespace prefix for the FHIR namespace, and "x" for the xhtml namespace, and SHALL NOT use any other prefixes.
Note: we are considering deprecating the xpath element. Implementer feedback is welcome.
Requirements
Used in Schematron tests of the validity of the resource.
Path
StructureDefinition.snapshot.element.ElementDefinition.constraint.source
Id
ElementDefinition.constraint.source
Type
Cardinality
0 - 1
Definition
A reference to the original source of the constraint, for traceability purposes.
Comment
This is used when, e.g. rendering, where it is not useful to present inherited constraints when rendering the snapshot.
Path
StructureDefinition.snapshot.element.ElementDefinition.mustSupport
Id
ElementDefinition.mustSupport
Type
Cardinality
0 - 1
Definition
If true, implementations that produce or consume resources SHALL provide "support" for the element in some meaningful way. If false, the element may be ignored and not supported.
Comment
"Something useful" is context dependent and impossible to describe in the base FHIR specification. For this reason, tue mustSupport flag is never set to true by the FHIR specification itself - it is only set to true in profiles.
This is done in [Resource Profiles](profiling.html#mustsupport), where the profile labels an element as mustSupport=true. When a profile does this, it SHALL also make clear exactly what kind of "support" is required, as this can mean many things.
Note that an element that has the property IsModifier is not necessarily a "key" element (e.g. one of the important elements to make use of the resource), nor is it automatically mustSupport - however both of these things are more likely to be true for IsModifier elements than for other elements.
Requirements
Allows a profile to set expectations for system capabilities beyond merely respecting cardinality constraints.
Path
StructureDefinition.snapshot.element.ElementDefinition.isModifier
Id
ElementDefinition.isModifier
Type
Cardinality
0 - 1
Definition
If true, the value of this element affects the interpretation of the element or resource that contains it, and the value of the element cannot be ignored. Typically, this is used for status, negation and qualification codes. The effect of this is that the element cannot be ignored by systems: they SHALL either recognize the element and process it, and/or a pre-determination has been made that it is not relevant to their particular system.
Comment
Only the definition of an element can set IsModifier true - either the specification itself or where an extension is originally defined. Once set, it cannot be changed in derived profiles. An element/extension that has isModifier=true SHOULD also have a minimum cardinality of 1, so that there is no lack of clarity about what to do if it is missing. If it can be missing, the definition SHALL make the meaning of a missing element clear.
Requirements
Allows elements to be introduced into a specification that can't safely be ignored by applications that don't recognize them.
Path
StructureDefinition.snapshot.element.ElementDefinition.isSummary
Id
ElementDefinition.isSummary
Type
Cardinality
0 - 1
Definition
Whether the element should be included if a client requests a search with the parameter _summary=true.
Comment
Some resources include a set of simple metadata, and some very large data. This element is used to reduce the quantity of data returned in searches. Note that servers may pre-cache summarized resources for optimal performance, so servers may not support per-profile use of the isSummary flag. When a request is made with _summary=true, serailisers only include elements marked as 'isSummary = true'. Other than Attachment.data, all data type properties are included in the summary form. Modifier elements or elements with minimum cardinality = 1 must be marked as summary elements.
Requirements
Allow clients to search through large resources quickly.
Path
StructureDefinition.snapshot.element.ElementDefinition.binding
Id
ElementDefinition.binding
Type
Cardinality
0 - 1
Definition
Binds to a value set if this element is coded (code, Coding, CodeableConcept, Quantity), or the data types (string, uri).
Comment
For a CodeableConcept, when no codes are allowed - only text, use a binding of strength "required" with a description explaining that no coded values are allowed and what sort of information to put in the "text" element.
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
eld-12 [error]
ValueSet as a URI SHALL start with http:// or https:// or urn:
Condition
eld-11
Path
StructureDefinition.snapshot.element.ElementDefinition.binding.strength
Id
ElementDefinition.binding.strength
Type
Cardinality
1 - 1
Definition
Indicates the degree of conformance expectations associated with this binding - that is, the degree to which the provided value set must be adhered to in the instances.
Comment
For further discussion, see [Using Terminologies](terminologies.html).
Path
StructureDefinition.snapshot.element.ElementDefinition.binding.description
Id
ElementDefinition.binding.description
Type
Cardinality
0 - 1
Definition
Describes the intended use of this particular set of codes.
Comment
Path
StructureDefinition.snapshot.element.ElementDefinition.binding.valueSet[x]
Id
ElementDefinition.binding.valueSet[x]
Type
Cardinality
0 - 1
Definition
Points to the value set or external definition (e.g. implicit value set) that identifies the set of codes to be used. If the binding refers to an explicit value set - the normal case - then use a Reference(ValueSet) preferably containing the canonical URL for the value set. If the reference is to an implicit value set - usually, an IETF RFC that defines a grammar, such as mime types - then use a uri.
Comment
For value sets with a referenceResource, the display can contain the value set description. The reference may be version-specific or not.
Condition
eld-12
Path
StructureDefinition.snapshot.element.ElementDefinition.mapping
Id
ElementDefinition.mapping
Type
Cardinality
0 - *
Definition
Identifies a concept from an external specification that roughly corresponds to this element.
Comment
Mappings are not necessarily specific enough for safe translation.
Requirements
Provides guidance to implementers familiar with or converting content from other specifications.
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
Path
StructureDefinition.snapshot.element.ElementDefinition.mapping.identity
Id
ElementDefinition.mapping.identity
Type
Cardinality
1 - 1
Definition
An internal reference to the definition of a mapping.
Comment
Path
StructureDefinition.snapshot.element.ElementDefinition.mapping.map
Id
ElementDefinition.mapping.map
Type
Cardinality
1 - 1
Definition
Expresses what part of the target specification corresponds to this element.
Comment
For most mappings, the syntax is undefined. Syntax will be provided for mappings to the RIM. Multiple mappings may be possible and may include constraints on other resource elements that identify when a particular mapping applies.
Path
StructureDefinition.snapshot.element.ElementDefinition.mapping.comment
Id
ElementDefinition.mapping.comment
Type
Cardinality
0 - 1
Definition
Comments that provide information about the mapping or its use.
Comment
Path
StructureDefinition.differential
Id
StructureDefinition.differential
Type
Cardinality
0 - 1
Definition
A differential view is expressed relative to the base StructureDefinition - a statement of differences that it applies.
Comment
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
sdf-15a [error]
If the first element in a differential has no "." in the path, it has no type
sdf-20 [error]
No slicing on the root element
sdf-8a [error]
In any differential, all the elements must be in the specified type
Condition
sdf-6
Path
StructureDefinition.differential.element
Id
StructureDefinition.differential.element
Type
Cardinality
1 - *
Definition
Captures constraints on each element within the resource.
Comment
Path
StructureDefinition.differential.element.ElementDefinition.path
Id
ElementDefinition.path
Type
Cardinality
1 - 1
Definition
The path identifies the element and is expressed as a "."-separated list of ancestor elements, beginning with the name of the resource or extension.
Comment
Path
StructureDefinition.differential.element.ElementDefinition.representation
Id
ElementDefinition.representation
Type
Cardinality
0 - *
Definition
Codes that define how this element is represented in instances, when the deviation varies from the normal case.
Comment
In resources, this is rarely used except for special cases where the representation deviates from the normal, and can only be done in the base standard (and profiles must reproduce what the base standard does). This element is used quite commonly in Logical models when the logical models represent a specific serialization format (e.g. CDA, v2 etc).
Path
StructureDefinition.differential.element.ElementDefinition.sliceName
Id
ElementDefinition.sliceName
Type
Cardinality
0 - 1
Definition
The name of this element definition slice, when slicing is working. The name must be a token with no dots or spaces. This is a unique name referring to a specific set of constraints applied to this element, used to provide a name to different slices of the same element.
Comment
The name SHALL be unique within the structure within the context of the constrained resource element. (Though to avoid confusion, uniqueness across all elements is recommended.).
Requirements
May also be used for code generation purposes.
Path
StructureDefinition.differential.element.ElementDefinition.label
Id
ElementDefinition.label
Type
Cardinality
0 - 1
Definition
A single preferred label which is the text to display beside the element indicating its meaning or to use to prompt for the element in a user display or form.
Comment
See also the extension (http://hl7.org/fhir/StructureDefinition/elementdefinition-question)[extension-elementdefinition-question.html].
Path
StructureDefinition.differential.element.ElementDefinition.code
Id
ElementDefinition.code
Type
Cardinality
0 - *
Definition
A code that has the same meaning as the element in a particular terminology.
Comment
The concept SHALL be properly aligned with the data element definition and other constraints, as defined in the code system, including relationships, of any code listed here. Where multiple codes exist in a terminology that could correspond to the data element, the most granular code(s) should be selected, so long as they are not more restrictive than the data element itself. The mappings may be used to provide more or less granular or structured equivalences in the code system.
Requirements
Links the meaning of an element to an external terminology, and is very useful for searching and indexing.
Path
StructureDefinition.differential.element.ElementDefinition.code.Coding.system
Id
Coding.system
Type
Cardinality
0 - 1
Definition
The identification of the code system that defines the meaning of the symbol in the code.
Comment
The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.
Requirements
Need to be unambiguous about the source of the definition of the symbol.
Path
StructureDefinition.differential.element.ElementDefinition.code.Coding.version
Id
Coding.version
Type
Cardinality
0 - 1
Definition
The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured. and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.
Comment
Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.
Path
StructureDefinition.differential.element.ElementDefinition.code.Coding.code
Id
Coding.code
Type
Cardinality
0 - 1
Definition
A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).
Comment
Requirements
Need to refer to a particular code in the system.
Path
StructureDefinition.differential.element.ElementDefinition.code.Coding.display
Id
Coding.display
Type
Cardinality
0 - 1
Definition
A representation of the meaning of the code in the system, following the rules of the system.
Comment
Requirements
Need to be able to carry a human-readable meaning of the code for readers that do not know the system.
Path
StructureDefinition.differential.element.ElementDefinition.code.Coding.userSelected
Id
Coding.userSelected
Type
Cardinality
0 - 1
Definition
Indicates that this coding was chosen by a user directly - i.e. off a pick list of available items (codes or displays).
Comment
Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely.
Requirements
This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing.
Path
StructureDefinition.differential.element.ElementDefinition.slicing
Id
ElementDefinition.slicing
Type
Cardinality
0 - 1
Definition
Indicates that the element is sliced into a set of alternative definitions (i.e. in a structure definition, there are multiple different constraints on a single element in the base resource). Slicing can be used in any resource that has cardinality ..* on the base resource, or any resource with a choice of types. The set of slices is any elements that come after this in the element sequence that have the same path, until a shorter path occurs (the shorter path terminates the set).
Comment
The first element in the sequence, the one that carries the slicing, is the definition that applies to all the slices. This is based on the unconstrained element, but can apply any constraints as appropriate. This may include the common constraints on the children of the element.
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
eld-1 [error]
If there are no discriminators, there must be a definition
Path
StructureDefinition.differential.element.ElementDefinition.slicing.discriminator
Id
ElementDefinition.slicing.discriminator
Type
Cardinality
0 - *
Definition
Designates which child elements are used to discriminate between the slices when processing an instance. If one or more discriminators are provided, the value of the child elements in the instance data SHALL completely distinguish which slice the element in the resource matches based on the allowed values for those elements in each of the slices.
Comment
If there is no discriminator, the content is hard to process, so this should be avoided. If the base element has a cardinality of ..1, and there is a choice of types, the discriminator must be "@type".
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
Path
StructureDefinition.differential.element.ElementDefinition.slicing.discriminator.type
Id
ElementDefinition.slicing.discriminator.type
Type
Cardinality
1 - 1
Definition
How the element value is interpreted when discrimination is evaluated.
Comment
Path
StructureDefinition.differential.element.ElementDefinition.slicing.discriminator.path
Id
ElementDefinition.slicing.discriminator.path
Type
Cardinality
1 - 1
Definition
A FHIRPath expression, using a restricted subset of FHIRPath, that is used to identify the element on which discrimination is based.
Comment
The only FHIRPath functions that are allowed are resolve(), and extension(url).
Path
StructureDefinition.differential.element.ElementDefinition.slicing.description
Id
ElementDefinition.slicing.description
Type
Cardinality
0 - 1
Definition
A human-readable text description of how the slicing works. If there is no discriminator, this is required to be present to provide whatever information is possible about how the slices can be differentiated.
Comment
If it's really not possible to differentiate them, the design should be re-evaluated to make the content usable.
Condition
eld-1
Path
StructureDefinition.differential.element.ElementDefinition.slicing.ordered
Id
ElementDefinition.slicing.ordered
Type
Cardinality
0 - 1
Definition
If the matching elements have to occur in the same order as defined in the profile.
Comment
Order should only be required when it is a pressing concern for presentation. Profile authors should consider making the order a feature of the rules about the narrative, not the rules about the data - requiring ordered data makes the profile much less re-usable.
Path
StructureDefinition.differential.element.ElementDefinition.slicing.rules
Id
ElementDefinition.slicing.rules
Type
Cardinality
1 - 1
Definition
Whether additional slices are allowed or not. When the slices are ordered, profile authors can also say that additional slices are only allowed at the end.
Comment
Allowing additional elements makes for a much for flexible template - it's open for use in wider contexts, but also means that the content of the resource is not closed, and applications have to decide how to handle content not described by the profile.
Path
StructureDefinition.differential.element.ElementDefinition.short
Id
ElementDefinition.short
Type
Cardinality
0 - 1
Definition
A concise description of what this element means (e.g. for use in autogenerated summaries).
Comment
May change the term to provide language more appropriate to the context of the profile or to reflect slicing.
Path
StructureDefinition.differential.element.ElementDefinition.definition
Id
ElementDefinition.definition
Type
Cardinality
0 - 1
Definition
Provides a complete explanation of the meaning of the data element for human readability. For the case of elements derived from existing elements (e.g. constraints), the definition SHALL be consistent with the base definition, but convey the meaning of the element in the particular context of use of the resource.
Comment
It is easy for a different definition to change the meaning of an element and this can have nasty downstream consequences. Please be careful when providing definitions.
Requirements
To allow a user to state the usage of an element in a particular context.
Path
StructureDefinition.differential.element.ElementDefinition.comment
Id
ElementDefinition.comment
Type
Cardinality
0 - 1
Definition
Explanatory notes and implementation guidance about the data element, including notes about how to use the data properly, exceptions to proper use, etc.
Comment
If it is possible to capture usage rules using constraints, that mechanism should be used in preference to this element.
Path
StructureDefinition.differential.element.ElementDefinition.requirements
Id
ElementDefinition.requirements
Type
Cardinality
0 - 1
Definition
This element is for traceability of why the element was created and why the constraints exist as they do. This may be used to point to source materials or specifications that drove the structure of this element.
Comment
This element does not describe the usage of the element (that's done in comments), rather it's for traceability of *why* the element is either needed or why the constraints exist as they do. This may be used to point to source materials or specifications that drove the structure of this data element.
Path
StructureDefinition.differential.element.ElementDefinition.alias
Id
ElementDefinition.alias
Type
Cardinality
0 - *
Definition
Identifies additional names by which this element might also be known.
Comment
Requirements
Allows for better easier recognition of the element by multiple communities, including international communities.
Path
StructureDefinition.differential.element.ElementDefinition.min
Id
ElementDefinition.min
Type
Cardinality
0 - 1
Definition
The minimum number of times this element SHALL appear in the instance.
Comment
Condition
eld-2
Path
StructureDefinition.differential.element.ElementDefinition.max
Id
ElementDefinition.max
Type
Cardinality
0 - 1
Definition
The maximum number of times this element is permitted to appear in the instance.
Comment
Constraint
eld-3 [error]
Max SHALL be a number or "*"
Condition
eld-3
eld-2
Path
StructureDefinition.differential.element.ElementDefinition.base
Id
ElementDefinition.base
Type
Cardinality
0 - 1
Definition
Information about the base definition of the element, provided to make it unnecessary for tools to trace the deviation of the element through the derived and related profiles. This information is provided when the element definition is not the original definition of an element - i.g. either in a constraint on another type, or for elements from a super type in a snap shot.
Comment
The base information does not carry any information that could not be determined from the path and related profiles, but making this determination requires both that the related profiles are available, and that the algorithm to determine them be available. So they are deformalised into this location for tooling convenience, and to ensure that the base information is available without dependencies.
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
Path
StructureDefinition.differential.element.ElementDefinition.base.path
Id
ElementDefinition.base.path
Type
Cardinality
1 - 1
Definition
The Path that identifies the base element - this matches the ElementDefinition.path for that element. Across FHIR, there is only one base definition of any element - that is, an element definition on a [StructureDefinition](structuredefinition.html#) without a StructureDefinition.base.
Comment
Path
StructureDefinition.differential.element.ElementDefinition.base.min
Id
ElementDefinition.base.min
Type
Cardinality
1 - 1
Definition
Minimum cardinality of the base element identified by the path.
Comment
This is provided for consistency with max, and may affect code generation of mandatory elements of the base resource are generated differently (some reference implementations have done this).
Path
StructureDefinition.differential.element.ElementDefinition.base.max
Id
ElementDefinition.base.max
Type
Cardinality
1 - 1
Definition
Maximum cardinality of the base element identified by the path.
Comment
This is provided to code generation, since the serialization representation in JSON differs depending on whether the base element has max > 1. Also, some forms of code generation may differ.
Path
StructureDefinition.differential.element.ElementDefinition.contentReference
Id
ElementDefinition.contentReference
Type
Cardinality
0 - 1
Definition
Identifies the identity of an element defined elsewhere in the profile whose content rules should be applied to the current element.
Comment
Condition
eld-5
Path
StructureDefinition.differential.element.ElementDefinition.type
Id
ElementDefinition.type
Type
Cardinality
0 - *
Definition
The data type or resource that the value of this element is permitted to be.
Comment
The Type of the element can be left blank in a differential constraint, in which case the type is inherited from the resource. Abstract types are not permitted to appear as a type when multiple types are listed. (I.e. Abstract types cannot be part of a choice).
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
eld-4 [error]
Aggregation may only be specified if one of the allowed types for the element is a resource
Condition
eld-13
Path
StructureDefinition.differential.element.ElementDefinition.type.code
Id
ElementDefinition.type.code
Type
Cardinality
1 - 1
Definition
URL of Data type or Resource that is a(or the) type used for this element. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition e.g. "string" is a reference to http://hl7.org/fhir/StructureDefinition/string. Absolute URLs are only allowed in logical models.
Comment
If the element is a reference to another resource, this element contains "Reference", and the targetProfile element defines what resources can be referenced. The targetProfile may be a reference to the general definition of a resource (e.g. http://hl7.org/fhir/StructureDefinition/Patient). There would be one pair of type/code for each allowed target resource type.
Path
StructureDefinition.differential.element.ElementDefinition.type.profile
Id
ElementDefinition.type.profile
Type
Cardinality
0 - 1
Definition
Identifies a profile structure or implementation Guide that SHALL hold for the datatype this element refers to. Can be a local reference - to a contained StructureDefinition, or a reference to another StructureDefinition or Implementation Guide by a canonical URL. When an implementation guide is specified, the resource SHALL conform to at least one profile defined in the implementation guide.
Comment
Path
StructureDefinition.differential.element.ElementDefinition.type.targetProfile
Id
ElementDefinition.type.targetProfile
Type
Cardinality
0 - 1
Definition
Identifies a profile structure or implementation Guide that SHALL hold for the target of the reference this element refers to. Can be a local reference - to a contained StructureDefinition, or a reference to another StructureDefinition or Implementation Guide by a canonical URL. When an implementation guide is specified, the resource SHALL conform to at least one profile defined in the implementation guide.
Comment
Path
StructureDefinition.differential.element.ElementDefinition.type.aggregation
Id
ElementDefinition.type.aggregation
Type
Cardinality
0 - *
Definition
If the type is a reference to another resource, how the resource is or can be aggregated - is it a contained resource, or a reference, and if the context is a bundle, is it included in the bundle.
Comment
Condition
eld-4
Path
StructureDefinition.differential.element.ElementDefinition.type.versioning
Id
ElementDefinition.type.versioning
Type
Cardinality
0 - 1
Definition
Whether this reference needs to be version specific or version independent, or whether either can be used.
Comment
The base specification never makes a rule as to which form is allowed, but implementation guides may do this.
Path
StructureDefinition.differential.element.ElementDefinition.defaultValue[x]
Id
ElementDefinition.defaultValue[x]
Type
Cardinality
0 - 1
Definition
The value that should be used if there is no value stated in the instance (e.g. 'if not otherwise specified, the abstract is false').
Comment
Default values can only be specified on a resource, data type, or extension definition, and never in a profile that applies to one of these. Specifying a default value means that the property can never been unknown - it must always have a value. Further, the default value can never be changed. For these reasons, default values are (and should be) used extremely sparingly.
Condition
eld-15
Path
StructureDefinition.differential.element.ElementDefinition.meaningWhenMissing
Id
ElementDefinition.meaningWhenMissing
Type
Cardinality
0 - 1
Definition
The Implicit meaning that is to be understood when this element is missing (e.g. 'when this element is missing, the period is ongoing'.
Comment
Implicit meanings for missing values can only be specified on a resource, data type, or extension definition, and never in a profile that applies to one of these. An implicit meaning for a missing value can never be changed, and specifying one has the consequence that constraining its use in profiles eliminates use cases as possibilities, not merely moving them out of scope.
Condition
eld-15
Path
StructureDefinition.differential.element.ElementDefinition.orderMeaning
Id
ElementDefinition.orderMeaning
Type
Cardinality
0 - 1
Definition
If present, indicates that the order of the repeating element has meaning and describes what that meaning is. If absent, it means that the order of the element has no meaning.
Comment
This element can only be asserted on repeating elements and can only be introduced when defining resources or data types. It can be further refined profiled elements but if absent in the base type, a profile cannot assert meaning.
Path
StructureDefinition.differential.element.ElementDefinition.fixed[x]
Id
ElementDefinition.fixed[x]
Type
Cardinality
0 - 1
Definition
Specifies a value that SHALL be exactly the value for this element in the instance. For purposes of comparison, non-significant whitespace is ignored, and all values must be an exact match (case and accent sensitive). Missing elements/attributes must also be missing.
Comment
This is not recommended for Coding and CodeableConcept since these often have highly contextual properties such as version or display.
Condition
eld-5
eld-6
eld-8
Path
StructureDefinition.differential.element.ElementDefinition.pattern[x]
Id
ElementDefinition.pattern[x]
Type
Cardinality
0 - 1
Definition
Specifies a value that the value in the instance SHALL follow - that is, any value in the pattern must be found in the instance. Other additional values may be found too. This is effectively constraint by example. The values of elements present in the pattern must match exactly (case-sensitive, accent-sensitive, etc.).
Comment
Mostly used for fixing values of CodeableConcept. At present, pattern[x] is not recommended as a basis for slicing while issues related to this are investigated during the STU period.
Condition
eld-5
eld-7
eld-8
Path
StructureDefinition.differential.element.ElementDefinition.example
Id
ElementDefinition.example
Type
Cardinality
0 - *
Definition
A sample value for this element demonstrating the type of information that would typically be found in the element.
Comment
Examples will most commonly be present for data where it's not implicitly obvious from either the data type or value set what the values might be. (I.e. Example values for dates or quantities would generally be unnecessary.) If the example value is fully populated, the publication tool can generate an instance automatically.
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
Path
StructureDefinition.differential.element.ElementDefinition.example.label
Id
ElementDefinition.example.label
Type
Cardinality
1 - 1
Definition
Describes the purpose of this example amoung the set of examples.
Comment
Path
StructureDefinition.differential.element.ElementDefinition.example.value[x]
Id
ElementDefinition.example.value[x]
Type
Cardinality
1 - 1
Definition
The actual value for the element, which must be one of the types allowed for this element.
Comment
Path
StructureDefinition.differential.element.ElementDefinition.minValue[x]
Id
ElementDefinition.minValue[x]
Type
Cardinality
0 - 1
Definition
The minimum allowed value for the element. The value is inclusive. This is allowed for the types date, dateTime, instant, time, decimal, integer, and Quantity.
Comment
Except for date/date/instant, the type of the minValue[x] SHALL be the same as the specified type of the element. For the date/dateTime/instant values, the type of minValue[x] SHALL be either the same, or a a [Duration](datatypes.html#duration) which specifies a relative time limit to the current time. The duration value is positive, and is subtracted from the current clock to determine the minimum allowable value. A minimum value for a Quantity is interpreted as an canonical minimum - e.g. you cannot provide 100mg if the minimum value is 10g.
Path
StructureDefinition.differential.element.ElementDefinition.maxValue[x]
Id
ElementDefinition.maxValue[x]
Type
Cardinality
0 - 1
Definition
The maximum allowed value for the element. The value is inclusive. This is allowed for the types date, dateTime, instant, time, decimal, integer, and Quantity.
Comment
Except for date/date/instant, the type of the maxValue[x] SHALL be the same as the specified type of the element. For the date/dateTime/instant values, the type of maxValue[x] SHALL be either the same, or a a [Duration](datatypes.html#duration) which specifies a relative time limit to the current time. The duration value is positive, and is added to the current clock to determine the maximum allowable value. A maximum value for a Quantity is interpreted as an canonical maximum - e.g. you cannot provide 10g if the maximum value is 50mg.
Path
StructureDefinition.differential.element.ElementDefinition.maxLength
Id
ElementDefinition.maxLength
Type
Cardinality
0 - 1
Definition
Indicates the maximum length in characters that is permitted to be present in conformant instances and which is expected to be supported by conformant consumers that support the element.
Comment
Receivers are not required to reject instances that exceed the maximum length. The full length could be stored. In some cases, data might be truncated, though truncation should be undertaken with care and an understanding of the consequences of doing so. If not specified, there is no conformance expectation for length support.
Path
StructureDefinition.differential.element.ElementDefinition.condition
Id
ElementDefinition.condition
Type
Cardinality
0 - *
Definition
A reference to an invariant that may make additional statements about the cardinality or value in the instance.
Comment
Path
StructureDefinition.differential.element.ElementDefinition.constraint
Id
ElementDefinition.constraint
Type
Cardinality
0 - *
Definition
Formal constraints such as co-occurrence and other constraints that can be computationally evaluated within the context of the instance.
Comment
Constraints should be declared on the "context" element - the lowest element in the hierarchy that is common to all nodes referenced by the constraint.
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
Path
StructureDefinition.differential.element.ElementDefinition.constraint.key
Id
ElementDefinition.constraint.key
Type
Cardinality
1 - 1
Definition
Allows identification of which elements have their cardinalities impacted by the constraint. Will not be referenced for constraints that do not affect cardinality.
Comment
Condition
eld-14
Path
StructureDefinition.differential.element.ElementDefinition.constraint.requirements
Id
ElementDefinition.constraint.requirements
Type
Cardinality
0 - 1
Definition
Description of why this constraint is necessary or appropriate.
Comment
To be used if the reason for the constraint may not be intuitive to all implementers.
Path
StructureDefinition.differential.element.ElementDefinition.constraint.severity
Id
ElementDefinition.constraint.severity
Type
Cardinality
1 - 1
Definition
Identifies the impact constraint violation has on the conformance of the instance.
Comment
This allows constraints to be asserted as "shall" (error) and "should" (warning).
Path
StructureDefinition.differential.element.ElementDefinition.constraint.human
Id
ElementDefinition.constraint.human
Type
Cardinality
1 - 1
Definition
Text that can be used to describe the constraint in messages identifying that the constraint has been violated.
Comment
Should be expressed in business terms as much as possible.
Path
StructureDefinition.differential.element.ElementDefinition.constraint.expression
Id
ElementDefinition.constraint.expression
Type
Cardinality
1 - 1
Definition
A [FHIRPath](http://hl7.org/fluentpath) expression of constraint that can be executed to see if this constraint is met.
Comment
Requirements
Used by validation tooling tests of the validity of the resource.
Path
StructureDefinition.differential.element.ElementDefinition.constraint.xpath
Id
ElementDefinition.constraint.xpath
Type
Cardinality
0 - 1
Definition
An XPath expression of constraint that can be executed to see if this constraint is met.
Comment
Elements SHALL use "f" as the namespace prefix for the FHIR namespace, and "x" for the xhtml namespace, and SHALL NOT use any other prefixes.
Note: we are considering deprecating the xpath element. Implementer feedback is welcome.
Requirements
Used in Schematron tests of the validity of the resource.
Path
StructureDefinition.differential.element.ElementDefinition.constraint.source
Id
ElementDefinition.constraint.source
Type
Cardinality
0 - 1
Definition
A reference to the original source of the constraint, for traceability purposes.
Comment
This is used when, e.g. rendering, where it is not useful to present inherited constraints when rendering the snapshot.
Path
StructureDefinition.differential.element.ElementDefinition.mustSupport
Id
ElementDefinition.mustSupport
Type
Cardinality
0 - 1
Definition
If true, implementations that produce or consume resources SHALL provide "support" for the element in some meaningful way. If false, the element may be ignored and not supported.
Comment
"Something useful" is context dependent and impossible to describe in the base FHIR specification. For this reason, tue mustSupport flag is never set to true by the FHIR specification itself - it is only set to true in profiles.
This is done in [Resource Profiles](profiling.html#mustsupport), where the profile labels an element as mustSupport=true. When a profile does this, it SHALL also make clear exactly what kind of "support" is required, as this can mean many things.
Note that an element that has the property IsModifier is not necessarily a "key" element (e.g. one of the important elements to make use of the resource), nor is it automatically mustSupport - however both of these things are more likely to be true for IsModifier elements than for other elements.
Requirements
Allows a profile to set expectations for system capabilities beyond merely respecting cardinality constraints.
Path
StructureDefinition.differential.element.ElementDefinition.isModifier
Id
ElementDefinition.isModifier
Type
Cardinality
0 - 1
Definition
If true, the value of this element affects the interpretation of the element or resource that contains it, and the value of the element cannot be ignored. Typically, this is used for status, negation and qualification codes. The effect of this is that the element cannot be ignored by systems: they SHALL either recognize the element and process it, and/or a pre-determination has been made that it is not relevant to their particular system.
Comment
Only the definition of an element can set IsModifier true - either the specification itself or where an extension is originally defined. Once set, it cannot be changed in derived profiles. An element/extension that has isModifier=true SHOULD also have a minimum cardinality of 1, so that there is no lack of clarity about what to do if it is missing. If it can be missing, the definition SHALL make the meaning of a missing element clear.
Requirements
Allows elements to be introduced into a specification that can't safely be ignored by applications that don't recognize them.
Path
StructureDefinition.differential.element.ElementDefinition.isSummary
Id
ElementDefinition.isSummary
Type
Cardinality
0 - 1
Definition
Whether the element should be included if a client requests a search with the parameter _summary=true.
Comment
Some resources include a set of simple metadata, and some very large data. This element is used to reduce the quantity of data returned in searches. Note that servers may pre-cache summarized resources for optimal performance, so servers may not support per-profile use of the isSummary flag. When a request is made with _summary=true, serailisers only include elements marked as 'isSummary = true'. Other than Attachment.data, all data type properties are included in the summary form. Modifier elements or elements with minimum cardinality = 1 must be marked as summary elements.
Requirements
Allow clients to search through large resources quickly.
Path
StructureDefinition.differential.element.ElementDefinition.binding
Id
ElementDefinition.binding
Type
Cardinality
0 - 1
Definition
Binds to a value set if this element is coded (code, Coding, CodeableConcept, Quantity), or the data types (string, uri).
Comment
For a CodeableConcept, when no codes are allowed - only text, use a binding of strength "required" with a description explaining that no coded values are allowed and what sort of information to put in the "text" element.
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
eld-12 [error]
ValueSet as a URI SHALL start with http:// or https:// or urn:
Condition
eld-11
Path
StructureDefinition.differential.element.ElementDefinition.binding.strength
Id
ElementDefinition.binding.strength
Type
Cardinality
1 - 1
Definition
Indicates the degree of conformance expectations associated with this binding - that is, the degree to which the provided value set must be adhered to in the instances.
Comment
For further discussion, see [Using Terminologies](terminologies.html).
Path
StructureDefinition.differential.element.ElementDefinition.binding.description
Id
ElementDefinition.binding.description
Type
Cardinality
0 - 1
Definition
Describes the intended use of this particular set of codes.
Comment
Path
StructureDefinition.differential.element.ElementDefinition.binding.valueSet[x]
Id
ElementDefinition.binding.valueSet[x]
Type
Cardinality
0 - 1
Definition
Points to the value set or external definition (e.g. implicit value set) that identifies the set of codes to be used. If the binding refers to an explicit value set - the normal case - then use a Reference(ValueSet) preferably containing the canonical URL for the value set. If the reference is to an implicit value set - usually, an IETF RFC that defines a grammar, such as mime types - then use a uri.
Comment
For value sets with a referenceResource, the display can contain the value set description. The reference may be version-specific or not.
Condition
eld-12
Path
StructureDefinition.differential.element.ElementDefinition.mapping
Id
ElementDefinition.mapping
Type
Cardinality
0 - *
Definition
Identifies a concept from an external specification that roughly corresponds to this element.
Comment
Mappings are not necessarily specific enough for safe translation.
Requirements
Provides guidance to implementers familiar with or converting content from other specifications.
Constraint
ele-1 [error]
All FHIR elements must have a @value or children
Path
StructureDefinition.differential.element.ElementDefinition.mapping.identity
Id
ElementDefinition.mapping.identity
Type
Cardinality
1 - 1
Definition
An internal reference to the definition of a mapping.
Comment
Path
StructureDefinition.differential.element.ElementDefinition.mapping.map
Id
ElementDefinition.mapping.map
Type
Cardinality
1 - 1
Definition
Expresses what part of the target specification corresponds to this element.
Comment
For most mappings, the syntax is undefined. Syntax will be provided for mappings to the RIM. Multiple mappings may be possible and may include constraints on other resource elements that identify when a particular mapping applies.
Path
StructureDefinition.differential.element.ElementDefinition.mapping.comment
Id
ElementDefinition.mapping.comment
Type
Cardinality
0 - 1
Definition
Comments that provide information about the mapping or its use.
Comment